Tomatoes - the most important vegetable crop
Economically, tomatoes are the most important vegetables worldwide. As tomatoes tolerate little rainfall yet still require a lot of water, heat and nutrients, cultivation under polythene or glass has proven beneficial. Determinate tomato varieties stop growing after the first flowering season, and indeterminate varieties continuously form additional leaf and shoot mass (up to 15m). There is a raft of tomato varieties available, for different growing times and cultivation methods and for various purposes. Tomatoes, like all nightshades, are susceptible to leaf diseases such as late blight (Phytophthora infestans), velvety blotches, powdery mildew and viruses. Continuously supplying the tomato plant with water and nutrients for as long as possible during the flowering and harvesting season, is economically crucial. Dry weather and low levels of fungal infection during harvesting are ideal to ensure a good shelf life.